The present invention relates to light fixtures and more particularly to refracting lenses for outdoor light fixtures.
As disclosed in co-pending, commonly-assigned U.S. patent application Ser. No. 07/742,917 and U.S. design patent applications Ser. Nos. 07/696,521, 07/696,528, 07/696,530 and 07/696,531, all filed May 7, 1991, outdoor light fixtures are widely known. Such fixtures typically are used to illuminate gardens, outdoor walkways, driveways, patios and other areas or to floodlight sculptures, trees, structures and other objects. Typically, low voltage outdoor light fixtures are constructed of metal or plastic, and have a power source, a stake for being inserted into the ground and for supporting the other parts of the light fixture, a light bulb, and a globe assembly that protects the light bulb, diffuses light emitted from the light bulb and provides decoration. In some fixtures, solar panels are used to generate power for the light bulb. In other fixtures, a low voltage power supply provides typically about 12 volts AC through a wire that runs, e.g., underground, from the low voltage power supply to the light fixtures.
In known outdoor light fixtures, the globe assembly generally serves a number of purposes, including: mounting the light bulb, conductively connecting the light bulb to a wire, protecting the light bulb, shielding the light bulb and associated electrical elements from dust and other contaminants, diffusing or redirecting the light emitted from the light bulb, and providing a decorative appearance.
It is desirable to diffuse or redirect the light to avoid large glaring hot spots. It is known to diffuse light by frosting lens portions of the globe assembly or by incorporating a translucent pigment. It is also known to refract light by incorporating ribs in the lens of the globe assembly. Such ribbed or frosted lenses are disclosed, for example, in U.S. Pat. Nos. 4,774,648 and 4,814,961.
Known globe assemblies incorporating translucent pigments, frosted surfaces or ribs possess a number of known disadvantages. One such disadvantage is diminished light output. Diminished light output occurs in frosted and translucent lenses and commonly is seen in commercial globe assemblies incorporating ribbed lenses.
A further disadvantage is that incorporating the refracting lens in the globe assembly decreases design flexibility. Often clear or unpatterned globe assemblies are preferable for aesthetic as well as functional reasons, such as efficient light transmission and staying cleaner in dusty outdoor conditions.
Yet another disadvantage is that the globe assembly must be removed in order to view the elements of the light fixture that are inside the globe to aid in installation and maintenance.